''Parvicursor'' (meaning "small runner") is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of tiny

maniraptora Maniraptora is a clade of coelurosaurian dinosaurs which includes the birds and the non-avian dinosaurs that were more closely related to them than to ''Ornithomimus velox''. It contains the major subgroups Avialae, Deinonychosauria, Oviraptoros ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

with long slender legs for fast running. At only about from snout to end of tail, and in weight, it was initially seen as one of the smallest non-avian dinosaurs known from an adult specimen.Which was the smallest dinosaur?
Royal Tyrrell Museum. Last accessed 2008-05-23. However, in 2022 its

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

was concluded to represent a juvenile individual. Like other members of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Alvarezsauridae Alvarezsauridae is a family of small, long-legged dinosaurs. Although originally thought to represent the earliest known flightless birds, they are now thought to be an early diverging branch of maniraptoran theropods. Alvarezsaurids were highly ...

, the forelimbs of ''Parvicursor'' were short and stubby, with hands all but completely reduced to a single large claw, possibly useful for opening tough

termite Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattode ...

mounds or other types of digging. It is unlikely that the claw could have served much for defense, as it was short and not adapted for flexible movements — it is more likely it would do as the animal's name implies: ''cursor'' means ''runner''. ''Parvicursor'' is known from the late

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...

-age

Barun Goyot Formation The Barun Goyot Formation (also known as Baruungoyot Formation or West Goyot Formation) is a geological formation dating to the Late Cretaceous Period. It is located within and is widely represented in the Gobi Desert Basin, in the Ömnögovi Pr ...

of Khulsan,

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...

, dated at approximately 72 million years old. The type species, ''Parvicursor remotus'', is only known from one incomplete specimen, holotype PIN no. 4487/25, mostly consisting of vertebrae, the

pelvis The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

and the right hindlimb, that was discovered in 1992 and described in 1996.Karhu, A.A. and Rautian, A.S. (1996). "A new family of Maniraptora (Dinosauria: Saurischia) from the Late Cretaceous of Mongolia". ''Paleontological Journal'' ''Russian Academy of Sciences'' 30(5): 583-592. Close relatives include ''

Shuvuuia ''Shuvuuia'' is a genus of bird-like theropod dinosaur from the late Cretaceous period of Mongolia. It is a member of the family Alvarezsauridae, small coelurosaurian dinosaurs which are characterized by short but powerful forelimbs specialized f ...

'' and ''

Mononykus ''Mononykus'' ( , sometimes ; meaning "one claw") is a genus of alvarezsaurid dinosaur that lived during the Late Cretaceous in what is now Asia on the Nemegt Formation, about 70 million years ago. ''Mononykus'' was a very small theropod, estim ...

'', and together with these it is classified in the alvarezsaurid subfamily

Parvicursorinae Alvarezsauridae is a family of small, long-legged dinosaurs. Although originally thought to represent the earliest known flightless birds, they are now thought to be an early diverging branch of maniraptoran theropods. Alvarezsaurids were highly ...

. There may be a second, yet-unnamed, species of ''Parvicursor''. Two specimens of tiny alvarezsaurids were described by Suzuki ''et al.'' in 2002. These authors considered the specimens to be juvenile ''

'', which lived in the same formation. However, a study by Nick Longrich and

Phil Currie Philip John Currie (born March 13, 1949) is a Canadian palaeontologist and museum curator who helped found the Royal Tyrrell Museum of Palaeontology in Drumheller, Alberta and is now a professor at the University of Alberta in Edmonton. In the ...

in 2009 suggested that several characters of the skeleton, including fused wrist and pelvic bones, indicated that these specimens were in fact adults of a tiny alvarezsaurid species. A

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analysis found that they grouped together with ''Parvicursor'', and the authors provisionally referred them to ''Parvicursor sp.'' pending further study. It has been suggested that ''

Linhenykus ''Linhenykus'' is an extinct genus of alvarezsaurid theropod dinosaur from the Late Cretaceous of Inner Mongolia, China. It is the most basal known member of the Parvicursorinae. The genus gets its name from Linhe, a city near the site where t ...

'' and ''

Ceratonykus ''Ceratonykus'' (meaning "horned claw") is a monospecific genus of alvarezsaurid dinosaur from Mongolia that lived during the Late Cretaceous (late Campanian stage, 72.1 Ma) in what is now the Barun Goyot Formation. The type and only species, ''C ...

'' may be junior synonyms of ''Parvicursor''.

References

{{Taxonbar, from=Q383329 Alvarezsaurids Late Cretaceous dinosaurs of Asia Fossil taxa described in 1996